The present invention relates to an electronic document circulation system for creating, circulating or processing an electronic document or form, and particularly to an effective electronic workflow control technology within a company or companies or an entity or entities or among any connection of them for use in an electronic circulation system for processing an electronic document or form over a plurality of workers distributed under the network circumstances.
W. Ford et al. xe2x80x9cSECURE ELECTRONIC COMMERCE, PRENTICE HALL PTR, pp. 111-117 and pp. 167-169, JP-A-8-329151 and JP-A-7-182431 describe Secure Socket Layers, Secure-HTTP, digital signature or stamp, encryption, decryption and workflow network.
Data containing documents and forms which are circulated within a conventional workflow system of a company or companies or individuals or individual and company encounters with a risk of unauthorized alteration during it is sequentially processed by respective workers.
According to the on-line shopping using WWW (World Wide Web), purchasers are able to select desired goods while watching a worldwide home page introducing goods at a desired time in the home and to apply for the selected goods by an electronic mail on the internet by inputting trade names and number of selected goods into an electronic form which is referred to as xe2x80x9cbasketxe2x80x9d or the like.
It is ideal to pay for the selected goods by using a credit card in a so-called cashless payment manner. However, if information such as credit card number were transmitted over the internet, such credit card number would have been abused by those who monitored the credit card number. Therefore, at present, credit card information is transmitted to the called party by other means such as Fax (facsimile).
In order to solve the problem of such inconvenient situations, as a tool in which an encryption function is assembled into WWW, authentication technologies and encryption technologies are applied to Secure Socket Layer (SSL). These technologies are effective as countermeasures such as xe2x80x9cReal called party?xe2x80x9d, xe2x80x9cCommunication contents are difficult to readxe2x80x9d, xe2x80x9ccommunication contents cannot be alteredxe2x80x9d for solving the problems of xe2x80x9cmasqueradexe2x80x9d, xe2x80x9cmonitoringxe2x80x9d and xe2x80x9cunauthorized alterationxe2x80x9d.
The SSL is one of encryption protocols and is able to encrypt all contents communicated via a Transmission Control Protocol/Internet Protocol (TCP/IP). Therefore, the SSL can cope with a variety of communication protocols such as Hyper Text Transfer Protocol (HTTP) for watching a home page, Simple Mail Transfer Protocol (SMTP) and Post Office Protocol (POP) for reading an electronic mail. In the case of WWW browser, it is possible to visually confirm from a picture by the display of a key mark whether or not a worker is authenticated correctly.
An electronic document comprises a plurality of tables and character strings (hereinafter referred to as formats) and data of each cell within the table (hereinafter referred to as data). In most cases, there is defined a calculation method of calculating data within a specific cell with reference to data of other cells except cells formed of data.
It is an object of the present invention to provide a technology in which a time necessary for encrypting and decrypting data such as electronic document and slip may be reduced and encrypted data may be displayed for only a specific worker.
It is another object of the present invention to provide a workflow system in which respective workers who check and process a plurality of divided data blocks within a document are inhibited from monitoring their checked/processed data blocks with each other.
It is other object of the present invention to provide a technology in which a displayed state of specific data may be controlled in response to an authorized duty of each worker.
It is a further object of the present invention to provide a technology in which the number of steps used to define a format for displaying electronic data may be reduced and electronic data may be displayed at high speed.
According to a first aspect of the present invention, there is provided a document circulation method of circulating a document having a plurality of data blocks. This circulation method comprises the steps of encrypting a certain data block of a plurality of data blocks in a document by using an encrypting key corresponding to a certain worker, encrypting another data block of a plurality of data blocks in the document by using another encrypting key corresponding to another worker and circulating the document having the certain data block and another data block over a network.
According to a second aspect of the present invention, there is provided a document circulation system for circulating a document having a plurality of data blocks. This document circulation system comprises an encrypting unit for encrypting a certain data block of a plurality of data blocks of a document by using an encrypting key corresponding to a certain worker and encrypting another data block of a plurality of data blocks of a document by using another encrypting key corresponding to another worker and a first apparatus having a transmitting unit for circulating the document having a certain data block and another data block through a network.
According to a third aspect of the present invention, there is provided a document circulation apparatus for circulating a document having a plurality of data blocks. This document circulation apparatus comprises an encrypting unit for encrypting a certain data block of a plurality of data blocks of a document by using an encrypting key corresponding to a certain worker and encrypting another data block of a plurality of data blocks of the document by using another encrypting key corresponding to another worker, a transmitting and receiving unit for circulating the document having a certain data block and another data block over a network and a display control unit for decrypting an encrypted portion of a document received from the network by using its own decrypting key and setting a display condition such that a data block which cannot be decrypted is not displayed.
According to a fourth aspect of the present invention, there is provided a storage medium for recording a document circulation program for circulating a document having a plurality of data blocks in such a manner that the document circulation program can be read by a computer. This storage medium comprises a code for the step of encrypting a certain data block of a plurality of data blocks of a document by using an encrypting key corresponding to a certain worker and encrypting another data block of a plurality of data blocks of the document by using an encrypting key corresponding to another worker and a code for the step of circulating the document having a certain data block and another data block over a network.
In accordance with a fifth aspect of the present invention, there is provided a storage medium for recording a document circulation program for circulating a document having a plurality of data blocks in such a manner that the document circulation program can be read by a computer. This storage medium comprises a code for the step of decrypting an encrypted portion of the document received from the network by using its own decrypting key and displaying the document except a data block which cannot be decrypted.
In accordance with a sixth aspect of the present invention, there is provided an electronic document processing method for circulating an electronic document having a plurality of data groups over a plurality of workers. This electronic document processing method comprises the steps of encrypting a certain data group of a plurality of data in an electronic document by using an encrypting key corresponding to a certain worker, transmitting an electronic document having the encrypted data group over a network, decrypting the encrypted data group of the electronic document by using a decrypting key corresponding to the worker and displaying whether or not the encrypted data group is decrypted correctly or displaying the document in response to the existence of the data group.
In accordance with a seventh aspect of the present invention, there is provided an electronic document processing system for circulating an electronic document having a plurality of data through a plurality of workers. This electronic document processing system comprises a first apparatus including a data encryption processing unit for encrypting a certain data of a plurality of data in an electronic document by using an encrypting key corresponding to a certain worker and a data input and output processing unit for transmitting and outputting an electronic document having the encrypted data over a network and a second apparatus including a data decryption processing unit for decrypting the encrypted data in the electronic document by using a decrypting key corresponding to the worker and a process defining and executing processing unit for displaying the data and effecting a processing in response to whether or not the encrypted specific form data is decrypted correctly or the existence of the form data.
In accordance with an eighth aspect of the present invention, there is provided a medium in which a program for enabling a computer to function as an electronic document processing system for circulating an electronic document having a plurality of data through a plurality of workers may be recorded in such a manner that the medium may be read and executed by a computer. This medium records programs for functioning a computer as a data encryption processing unit for encrypting specific data of a plurality of data in an electronic document by using an encrypting key corresponding to a specific worker, a data input and output processing unit for transmitting and receiving electronic data having the encrypted specific data over a network, data decryption processing unit for decrypting the encrypted specific data in the electronic data by a decrypting key corresponding to the specific worker, and a process defining and executing processing unit for displaying data and effecting a processing in response to whether or not the encrypted data is decoded correctly or the existence of the data.
In an electronic data circulation processing system in which an electronic document having a plurality of data are circulated to a plurality of workers, an electronic document in which specific data within a plurality of data is encrypted by an encrypting key corresponding to a specific worker is circulated among a plurality of workers, the encrypted data are decrypted by using a decrypting key of each worker, an electronic document including decrypted data is displayed and processed electronically.
In an electronic document processing system according to the present invention, specific data within a plurality of data within electronic document data is encrypted by using an encrypting key corresponding to a specific worker and electronic document data having the specific encrypted data is transmitted to another worker over the network.
The worker who received the electronic document having the encrypted data decrypts encrypted data within the electronic document by using a decrypting key of that worker.
If the worker who received the electronic document has a decrypting key corresponding to the encrypting key used in the encryption, encrypted data can be decrypted correctly. If not, then encrypted data cannot be decrypted.
When the encrypted specific data is decrypted correctly, the contents of the electronic document including decrypted data are displayed and the processing corresponding to the worker is executed.
When the encrypted specific data is not ecrypted correctly, under the condition that the display of encrypted data and the display of a cell which becomes a display frame used to display such data are restrained, electronic data is displayed and the processing corresponding to the worker is executed. At that time, the display of cells in which original data are not stored may be restrained.
Further, if a decrypting key is distributed to each worker in response to an authorized duty of each worker, then only a worker who has an authorized duty for referring to the data may refer to such data.
Furthermore, if information indicative of a display attribute of each data is set in a format, a display attribute of a format is changed in response to whether or not the encrypted specific data is decrypted correctly or the existence of the data and the display of the data and the display of such cell are restrained, then a plurality of formats need not be prepared in response to respective workers, and data may be displayed with a different format for every worker.
As described above, according to the electronic document processing system of the present invention, since specific data within a plurality of data in an electronic document is encrypted and decrypted by using the encrypting and decrypting keys corresponding to a specific worker, a time necessary for encrypting and decrypting the electronic document may be reduced, and encrypted data may be displayed for only a specific worker.